Powerpoint 12 Flashcards
What are three places Lead can be ingested from?
- contaminated water
- lead based paint
- other lead materials
What does Lead bind to once it enters the blood stream?
Red Blood Cells
Lead can cross the underdeveloped ______ of children to affect ______________ neurons crucial for learning and memory
BBB; hippocampal
When Lead binds to the NMDR receptor, what does it block?
Glutamate
Once lead binds to the NMDA receptor and blocks glutamate, what happens to the calcium levels and nitric oxide synthase levels?
Calcium levels decrease and nitric oxide synthase levels increase
What is the NMDA receptor important for?
Learning
Under normal physiological conditions, there is a balance between ____ ______ and_____________ and any deviation from it can cause oxidative stress leading to cell death
Free radicals; antioxidants
What is included in Antioxidant Defense
GSH
GST
SOD
GPx
Catalase
What is involved in ROS Production?
O2
H2O2
RO
NO
ONOO
OH
Oxidative leads to what three things that lead to cell death?
- Protein
- Lipid
- DNA
Direct neurotoxic effects on neurons include:
- Apoptosis
- Excitotoxicity
- synapse formation and function
- General protein information and function
- Adverse affects on astrocytes and oligodendrocytes
- others
What is induced by lead exposure; most likely through causing mitochondrial damage and/or disrupted calcium homeostasis?
Apoptosis
What comes about indirectly through abnormal mitochondrial function - causing glutamate induced neuronal cell death?
Excitotoxicity
What substitutes for calcium and zinc and affects the activity of second messengers and many different protein function, and has significant effects of lead on synaptic development and function?
Lead
Pb2+ has a _______ affinity for thiol groups than Zn2+
Greater
Pb2+ _______ Ca2+, binds to active sites in Ca-dependent proteins, but even more potent activator than Ca2+ -> abnormal activation
Mimics
when Pb displaces/replaces Zn, what does that lead to?
Inhibition of protein function
What impairs mitochondrial functions during synaptogenesis?
Pb2+
what does Pb2+ impair at the axon terminal which eventually limits the energy related activities?
ATP synthesis
What plays a critical role in learning and memory?
Dentate gyrus and Cornu ammonis area 3(CA) of hippocampus
What type of channels does Lead inhibit?
voltage-gated calcium ion channels
True or False: Lead interrupts Calcium signaling
True
True or False: Lead exposure has a large effect on dendritic length
False, it does not have much of an effect on dendritic length
What are the three main shapes of Dendritic spines?
- Mushroom
- Thin
- Stubby
Mushroom spine length affects ____ influx into the dendrite
Ca2+
mushroom spines mediate stronger synaptic transmission, so they are thought to be what kind of spine?
Memory spines
Reducing the number of mushroom spines leads to what kind of effect on learning and memory?
Detrimental
Which type of dendritic spine has larger PSDs and contain more receptors?
Mushroom spines
True or False: Lead exposure decreases the number of mushroom spines present
True
which dendritic spine does this describe?
Small head and narrow neck
Thin
Which dendritic spine does this describe?
Large head and narrow neck
Mushroom
Which dendritic spine does this describe?
No obvious neck
Stubby
What are the major risk factors for neurodegenerative diseases?
- age
- genetics
- environment factors
